Create barebones Todo API with FastAPI and SQLite

README.md

@@ -1,3 +1,93 @@
-# FastAPI Application
+# Barebones Todo API
 
-This is a FastAPI application bootstrapped by BackendIM, the AI-powered backend generation platform.
+A simple, lightweight RESTful API for managing todo items built with FastAPI and SQLite.
+
+## Features
+
+- Create, read, update, and delete todo items
+- Filter todos by completion status
+- SQLite database for data persistence
+- FastAPI for high performance and automatic API documentation
+- Alembic for database migrations
+
+## Project Structure
+
+```
+├── app/
+│   ├── api/              # API routes
+│   │   └── v1/           # API version 1
+│   │       └── endpoints/
+│   │           └── todos.py
+│   ├── core/             # Core application code
+│   │   └── config.py     # Configuration settings
+│   ├── db/               # Database setup
+│   │   ├── base.py
+│   │   ├── base_class.py
+│   │   └── session.py
+│   ├── models/           # SQLAlchemy models
+│   │   └── todo.py
+│   └── schemas/          # Pydantic schemas
+│       └── todo.py
+├── migrations/           # Alembic migrations
+├── storage/              # Storage directory
+│   └── db/               # Database storage
+├── alembic.ini           # Alembic configuration
+├── main.py               # Application entry point
+└── requirements.txt      # Project dependencies
+```
+
+## Installation
+
+1. Clone the repository
+
+2. Install dependencies
+```bash
+pip install -r requirements.txt
+```
+
+3. Apply database migrations
+```bash
+alembic upgrade head
+```
+
+## Running the API
+
+Start the API server with:
+```bash
+uvicorn main:app --reload
+```
+
+The API will be available at http://localhost:8000
+
+## API Documentation
+
+- Swagger UI: http://localhost:8000/docs
+- ReDoc: http://localhost:8000/redoc
+- OpenAPI JSON: http://localhost:8000/openapi.json
+
+## API Endpoints
+
+### Base URL
+- `GET /` - Returns basic API information
+- `GET /health` - Health check endpoint
+
+### Todo Endpoints
+- `GET /api/v1/todos` - List all todos (with optional filters)
+- `POST /api/v1/todos` - Create a new todo
+- `GET /api/v1/todos/{todo_id}` - Retrieve a specific todo
+- `PUT /api/v1/todos/{todo_id}` - Update a todo
+- `DELETE /api/v1/todos/{todo_id}` - Delete a todo
+
+## Database Migrations
+
+This project uses Alembic for database migrations. To create a new migration after model changes:
+
+```bash
+alembic revision --autogenerate -m "Description of changes"
+```
+
+To apply migrations:
+
+```bash
+alembic upgrade head
+```

alembic.ini

@@ -0,0 +1,85 @@
+# A generic, single database configuration.
+
+[alembic]
+# path to migration scripts
+script_location = migrations
+
+# template used to generate migration files
+# file_template = %%(rev)s_%%(slug)s
+
+# timezone to use when rendering the date
+# within the migration file as well as the filename.
+# string value is passed to dateutil.tz.gettz()
+# leave blank for localtime
+# timezone =
+
+# max length of characters to apply to the
+# "slug" field
+# truncate_slug_length = 40
+
+# set to 'true' to run the environment during
+# the 'revision' command, regardless of autogenerate
+# revision_environment = false
+
+# set to 'true' to allow .pyc and .pyo files without
+# a source .py file to be detected as revisions in the
+# versions/ directory
+# sourceless = false
+
+# version location specification; this defaults
+# to migrations/versions.  When using multiple version
+# directories, initial revisions must be specified with --version-path
+# version_locations = %(here)s/bar %(here)s/bat migrations/versions
+
+# the output encoding used when revision files
+# are written from script.py.mako
+# output_encoding = utf-8
+
+# SQLite URL with absolute path
+sqlalchemy.url = sqlite:////app/storage/db/db.sqlite
+
+[post_write_hooks]
+# post_write_hooks defines scripts or Python functions that are run
+# on newly generated revision scripts.  See the documentation for further
+# detail and examples
+
+# format using "black" - use the console_scripts runner, against the "black" entrypoint
+# hooks=black
+# black.type=console_scripts
+# black.entrypoint=black
+# black.options=-l 79
+
+# Logging configuration
+[loggers]
+keys = root,sqlalchemy,alembic
+
+[handlers]
+keys = console
+
+[formatters]
+keys = generic
+
+[logger_root]
+level = WARN
+handlers = console
+qualname =
+
+[logger_sqlalchemy]
+level = WARN
+handlers =
+qualname = sqlalchemy.engine
+
+[logger_alembic]
+level = INFO
+handlers =
+qualname = alembic
+
+[handler_console]
+class = StreamHandler
+args = (sys.stderr,)
+level = NOTSET
+formatter = generic
+
+[formatter_generic]
+format = %(levelname)-5.5s [%(name)s] %(message)s
+datefmt = %H:%M:%S

app/__init__.py

@@ -0,0 +1 @@
+# app package initialization

app/api/__init__.py

@@ -0,0 +1 @@
+# API package initialization

app/api/v1/__init__.py

@@ -0,0 +1 @@
+# API v1 package initialization

app/api/v1/api.py

@@ -0,0 +1,5 @@
+from fastapi import APIRouter
+from app.api.v1.endpoints import todos
+
+api_router = APIRouter(prefix="/api/v1")
+api_router.include_router(todos.router, prefix="/todos", tags=["todos"])

app/api/v1/endpoints/__init__.py

@@ -0,0 +1 @@
+# Endpoints package initialization

app/api/v1/endpoints/todos.py

@@ -0,0 +1,92 @@
+from typing import List, Optional
+from fastapi import APIRouter, Depends, HTTPException, status
+from sqlalchemy.orm import Session
+
+from app.db.session import get_db
+from app.models.todo import Todo as TodoModel
+from app.schemas.todo import Todo, TodoCreate, TodoUpdate
+
+router = APIRouter()
+
+@router.get("/", response_model=List[Todo])
+def read_todos(
+    skip: int = 0, 
+    limit: int = 100, 
+    completed: Optional[bool] = None,
+    db: Session = Depends(get_db)
+):
+    """
+    Retrieve todos with optional filtering by completion status.
+    """
+    if completed is not None:
+        return db.query(TodoModel).filter(TodoModel.completed == completed).offset(skip).limit(limit).all()
+    return db.query(TodoModel).offset(skip).limit(limit).all()
+
+
+@router.post("/", response_model=Todo, status_code=status.HTTP_201_CREATED)
+def create_todo(
+    todo: TodoCreate, 
+    db: Session = Depends(get_db)
+):
+    """
+    Create a new todo item.
+    """
+    db_todo = TodoModel(**todo.model_dump())
+    db.add(db_todo)
+    db.commit()
+    db.refresh(db_todo)
+    return db_todo
+
+
+@router.get("/{todo_id}", response_model=Todo)
+def read_todo(
+    todo_id: int, 
+    db: Session = Depends(get_db)
+):
+    """
+    Get a specific todo by ID.
+    """
+    db_todo = db.query(TodoModel).filter(TodoModel.id == todo_id).first()
+    if db_todo is None:
+        raise HTTPException(status_code=404, detail="Todo not found")
+    return db_todo
+
+
+@router.put("/{todo_id}", response_model=Todo)
+def update_todo(
+    todo_id: int, 
+    todo: TodoUpdate, 
+    db: Session = Depends(get_db)
+):
+    """
+    Update a todo item.
+    """
+    db_todo = db.query(TodoModel).filter(TodoModel.id == todo_id).first()
+    if db_todo is None:
+        raise HTTPException(status_code=404, detail="Todo not found")
+    
+    update_data = todo.model_dump(exclude_unset=True)
+    for key, value in update_data.items():
+        setattr(db_todo, key, value)
+    
+    db.add(db_todo)
+    db.commit()
+    db.refresh(db_todo)
+    return db_todo
+
+
+@router.delete("/{todo_id}", status_code=status.HTTP_204_NO_CONTENT, response_model=None)
+def delete_todo(
+    todo_id: int, 
+    db: Session = Depends(get_db)
+):
+    """
+    Delete a todo item.
+    """
+    db_todo = db.query(TodoModel).filter(TodoModel.id == todo_id).first()
+    if db_todo is None:
+        raise HTTPException(status_code=404, detail="Todo not found")
+    
+    db.delete(db_todo)
+    db.commit()
+    return None

app/core/__init__.py

@@ -0,0 +1 @@
+# Core package initialization

app/core/config.py

@@ -0,0 +1,28 @@
+from pathlib import Path
+from pydantic import field_validator
+from pydantic_settings import BaseSettings
+
+# Build paths
+BASE_DIR = Path(__file__).resolve().parent.parent.parent
+
+class Settings(BaseSettings):
+    PROJECT_NAME: str = "Barebones Todo API"
+    API_V1_STR: str = "/api/v1"
+    
+    # SQLite Database settings
+    DB_DIR: Path = BASE_DIR / "storage" / "db"
+    SQLALCHEMY_DATABASE_URL: str = f"sqlite:///{DB_DIR}/db.sqlite"
+    
+    @field_validator("SQLALCHEMY_DATABASE_URL")
+    def validate_db_url(cls, v, values):
+        # Ensure directory exists
+        db_dir = values.data.get("DB_DIR")
+        if db_dir:
+            db_dir.mkdir(parents=True, exist_ok=True)
+        return v
+
+    class Config:
+        env_file = ".env"
+        case_sensitive = True
+
+settings = Settings()

app/db/__init__.py

@@ -0,0 +1 @@
+# Database package initialization

app/db/base.py

@@ -0,0 +1,4 @@
+# Import all the models, so that Base has them before being
+# imported by Alembic
+from app.db.base_class import Base  # noqa
+from app.models.todo import Todo  # noqa

app/db/base_class.py

@@ -0,0 +1,12 @@
+from typing import Any
+from sqlalchemy.ext.declarative import as_declarative, declared_attr
+
+@as_declarative()
+class Base:
+    id: Any
+    __name__: str
+    
+    # Generate tablename automatically
+    @declared_attr
+    def __tablename__(cls) -> str:
+        return cls.__name__.lower()

app/db/session.py

@@ -0,0 +1,24 @@
+from pathlib import Path
+from sqlalchemy import create_engine
+from sqlalchemy.orm import sessionmaker
+
+
+# Ensure directory exists
+DB_DIR = Path("/app") / "storage" / "db"
+DB_DIR.mkdir(parents=True, exist_ok=True)
+
+SQLALCHEMY_DATABASE_URL = f"sqlite:///{DB_DIR}/db.sqlite"
+
+engine = create_engine(
+    SQLALCHEMY_DATABASE_URL,
+    connect_args={"check_same_thread": False}
+)
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+
+# Dependency to get DB session
+def get_db():
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()

app/models/__init__.py

@@ -0,0 +1 @@
+# Models package initialization

app/models/todo.py

@@ -0,0 +1,12 @@
+from datetime import datetime
+from sqlalchemy import Boolean, Column, Integer, String, DateTime
+
+from app.db.base_class import Base
+
+class Todo(Base):
+    id = Column(Integer, primary_key=True, index=True)
+    title = Column(String, index=True)
+    description = Column(String, nullable=True)
+    completed = Column(Boolean, default=False)
+    created_at = Column(DateTime, default=datetime.utcnow)
+    updated_at = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)

app/schemas/__init__.py

@@ -0,0 +1,6 @@
+# Schemas package initialization
+from app.schemas.todo import Todo as Todo
+from app.schemas.todo import TodoCreate as TodoCreate
+from app.schemas.todo import TodoUpdate as TodoUpdate
+
+__all__ = ["Todo", "TodoCreate", "TodoUpdate"]

app/schemas/todo.py

@@ -0,0 +1,32 @@
+from datetime import datetime
+from typing import Optional
+
+from pydantic import BaseModel
+
+# Shared properties
+class TodoBase(BaseModel):
+    title: str
+    description: Optional[str] = None
+    completed: bool = False
+
+# Properties to receive on todo creation
+class TodoCreate(TodoBase):
+    pass
+
+# Properties to receive on todo update
+class TodoUpdate(TodoBase):
+    title: Optional[str] = None
+    completed: Optional[bool] = None
+
+# Properties shared by models stored in DB
+class TodoInDBBase(TodoBase):
+    id: int
+    created_at: datetime
+    updated_at: datetime
+
+    class Config:
+        from_attributes = True
+
+# Properties to return to client
+class Todo(TodoInDBBase):
+    pass

main.py

@@ -0,0 +1,40 @@
+import uvicorn
+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+from app.api.v1.api import api_router
+from app.core.config import settings
+
+app = FastAPI(
+    title=settings.PROJECT_NAME,
+    openapi_url="/openapi.json",
+    version="0.1.0",
+)
+
+# Set up CORS middleware
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+# Include API router
+app.include_router(api_router)
+
+# Root endpoint
+@app.get("/")
+async def root():
+    return {
+        "title": settings.PROJECT_NAME,
+        "docs": "/docs",
+        "health": "/health"
+    }
+
+# Health check endpoint
+@app.get("/health")
+async def health_check():
+    return {"status": "healthy"}
+
+if __name__ == "__main__":
+    uvicorn.run("main:app", host="0.0.0.0", port=8000, reload=True)

migrations/README

@@ -0,0 +1 @@
+Generic single-database configuration with SQLite.

migrations/env.py

@@ -0,0 +1,74 @@
+import os
+import sys
+from logging.config import fileConfig
+
+from sqlalchemy import engine_from_config
+from sqlalchemy import pool
+
+from alembic import context
+
+# Add the project root directory to the Python path so we can import app
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+# Import Base from the app
+from app.db.base import Base  # noqa
+
+# This is the Alembic Config object
+config = context.config
+
+# Interpret the config file for Python logging
+fileConfig(config.config_file_name)
+
+# Import all models for Alembic to detect
+target_metadata = Base.metadata
+
+def run_migrations_offline():
+    """Run migrations in 'offline' mode.
+
+    This configures the context with just a URL
+    and not an Engine, though an Engine is acceptable
+    here as well.  By skipping the Engine creation
+    we don't even need a DBAPI to be available.
+
+    """
+    url = config.get_main_option("sqlalchemy.url")
+    context.configure(
+        url=url,
+        target_metadata=target_metadata,
+        literal_binds=True,
+        dialect_opts={"paramstyle": "named"},
+    )
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def run_migrations_online():
+    """Run migrations in 'online' mode.
+
+    In this scenario we need to create an Engine
+    and associate a connection with the context.
+
+    """
+    connectable = engine_from_config(
+        config.get_section(config.config_ini_section),
+        prefix="sqlalchemy.",
+        poolclass=pool.NullPool,
+    )
+
+    with connectable.connect() as connection:
+        is_sqlite = connection.dialect.name == 'sqlite'
+        context.configure(
+            connection=connection,
+            target_metadata=target_metadata,
+            render_as_batch=is_sqlite,  # Required for SQLite to handle ALTER TABLE operations properly
+        )
+
+        with context.begin_transaction():
+            context.run_migrations()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()

migrations/script.py.mako

@@ -0,0 +1,24 @@
+"""${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision | comma,n}
+Create Date: ${create_date}
+
+"""
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
+# revision identifiers, used by Alembic.
+revision = ${repr(up_revision)}
+down_revision = ${repr(down_revision)}
+branch_labels = ${repr(branch_labels)}
+depends_on = ${repr(depends_on)}
+
+
+def upgrade():
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade():
+    ${downgrades if downgrades else "pass"}

migrations/versions/01_initial_todos_table.py

@@ -0,0 +1,39 @@
+"""Initial todos table
+
+Revision ID: 001
+Revises: 
+Create Date: 2023-09-20
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = '001'
+down_revision = None
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # Create todos table
+    op.create_table(
+        'todo',
+        sa.Column('id', sa.Integer(), nullable=False),
+        sa.Column('title', sa.String(), nullable=False),
+        sa.Column('description', sa.String(), nullable=True),
+        sa.Column('completed', sa.Boolean(), default=False, nullable=False),
+        sa.Column('created_at', sa.DateTime(), nullable=False),
+        sa.Column('updated_at', sa.DateTime(), nullable=False),
+        sa.PrimaryKeyConstraint('id')
+    )
+    op.create_index(op.f('ix_todo_id'), 'todo', ['id'], unique=False)
+    op.create_index(op.f('ix_todo_title'), 'todo', ['title'], unique=False)
+
+
+def downgrade():
+    # Drop todos table
+    op.drop_index(op.f('ix_todo_title'), table_name='todo')
+    op.drop_index(op.f('ix_todo_id'), table_name='todo')
+    op.drop_table('todo')

requirements.txt

@@ -0,0 +1,7 @@
+fastapi>=0.103.1
+uvicorn>=0.23.2
+sqlalchemy>=2.0.20
+alembic>=1.12.0
+pydantic>=2.3.0
+python-dotenv>=1.0.0
+ruff>=0.0.290